Posted by NoNo100 on .
a handball is hit toward a wall with a velocity of 13.7 m/s in the forward direction. it returns with a velocity of 11.5 m/s in the backward direction. if the time interval during which the ball is accelerated is .021 s what is the handballs average acceleration?

Physics 
MathMate,
Force = rate of change of momentum.
Calculate the momentum (in terms of the mass m) before and after impact. Dividing by the duration of acceleration will give the force acted on the object (handball). Finally divide the force by the mass m will give the acceleration. It is likely to be a large number because of the small duration involved.